Typical Porsche Cayenne components continued

7

Accessibly situated right at the front of the engine bay is the electronicallyactivated throttle body assembly, which responds to accelerator input from the driver, without any mechanical linkage between the pedal and the throttle body.

8

Clean engine oil is imperative for the correct operation of all modern diesel engines, and it is essential that the Cayenne’s engine oil and the filter (casing shown here) are changed at least as often as recommended by Porsche, preferably far more frequently.

9

If ever it is necessary to jump-start the car, the special terminals provided for this purpose must be used. This is the negative (earth or ground) terminal, protruding from the left-hand inner wing area of the engine compartment.

10

The positive jump-start terminal is positioned adjacent to the bulkhead and close to the base of the bonnet-supporting strut. Cleanliness here is essential, as is ensuring that the terminal’s cover is not damaged.

11

Inspect the Lambda sensors, ensuring they are in good physical condition and the electrical cables/connections are sound. These sensors assess oxygen levels within the exhaust, so fuelling can be adjusted to optimum levels for catalytic converter operation.

12

The variable turbocharger activator is located at the rear of the engine bay. This controls the variable geometry turbocharger in response to driver demands on the engine; if more power is needed, greater boost pressure is developed accordingly.

13

Two oil pressure sensors are employed. The sensors report pressure to the ECU, in turn illuminating the dash warning lamp if necessary. The sensors are usually reliable, so if the lamp is flashing there is probably an oil pressure problem. It’s essential to use the correct specification oil.

14

The transmission’s transfer box is seen here from beneath the car. This unit is prone to moisture ingress, preventing correct operation. One symptom is juddering, akin to ‘clutch judder’ (see Fault 2).

15

These two complex harness plug assemblies (viewed here from under the car) serve the transmission system. Make sure the connections are clean and sound, and that the cables are in good condition, with insulation that has not been abraded or damaged.

16

There is no physical dipstick on this Cayenne, just an engine oil level sensor. Inspect the wiring and electrical connector assembly, making sure that there is no physical damage nor moisture ingress, etc.

17

The handbrake on this Porsche is electrically activated and this is one of the rear hub-mounted activators. These are located in a harsh operating environment, accessible to moisture and road salt. Check closely for signs of deterioration.

18

This Cayenne incorporates suspension level sensors, one per wheel. Again, due to the adverse conditions in which these have to operate, it is wise to check them regularly for correct operation and possible damage.